saving logs in codeigniter

logs.php

    /*audit trail*/



    private $logdir = "application/logs/";
    private $logfile;
    private $logs;

    private function writeFile($logs) {
        $fileOpen = fopen($this->logdir . $this->logfile, 'a+');
        fwrite($fileOpen, $logs);
        fclose($fileOpen);
    }

    protected function saveLogs($action = "null", $comment = "null") {
        $datetime = time();
        $this->logfile = "audittrail_" . date("mdY", $datetime) . ".csv";

        $this->logs =  $datetime . ',';
        $this->logs .= $_SERVER['SERVER_ADDR'] . ',';
        $this->logs .= self::ez_decrypt($this->session->userdata('user_id')) . ',';
        $this->logs .= '"' . self::ez_decrypt($this->session->userdata('user_email')) . '",';
        $this->logs .= '"' . $action .'",';
        $this->logs .= '"' . $comment . '",';
        $this->logs .= '"http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'] . '"';

        $this->writeFile("\r" . $this->logs);
    }